In postmenopausal osteoporosis the bone increasing effect of monofluorophosphate is not dependent on serum fluoride

According to previous pharmacokinetic studies the biovailability of fluorine (F) from sodium monofluorophosphate (MFP) doubles that of sodium fluoride (NaF). This paper reports a study designed to verify whether the vertebral bone mass increasing effect of NaF (30 mg F/day) was comparable to that of MFP (15 mg F/day), given for 18 months to osteoporotic postmenopausal women. The BMD of lumbar vertebrae of both groups showed significant increases (MFP: 60 + 15 mg/cm2, NaF: and 71 + 12 mg/cm2) over basal levels (P < 0.001). The difference between treatments was not significant (P = 0.532). The serum levels of ionic F (the mitogenic species on osteoblasts) were not related to the above mentioned effects. In NaF-treated patients, the fasting levels of total serum F increased significantly (6.7 + 0.9 muM vs. Basal: 2.0 + 0.8 muM; P < 0.001). This phenomenon was accounted for by ionic fluoride that increased over 20-fold (6.5 + 1.9 muM vs. Basal: 0.3 + 0.04 muM). In MFP-treated patients the fasting serum levels of total (7.0 + 0.7 muM vs. Basal: 2.2 + 0.9 M) and diffusible F (0.5 + 0.02 muM vs. Basal 0.2 + 0.02 muM) increased significantly (P < 0.001). The increase in the non diffussible F fraction is accounted for by proteinboud F, probably by the complexes formed between MFP and alpha2-macroglobulin and C3. Serum diffusible F was formed by two fractions: ionic F and F bound to low molecular weight macromolecule/s (2 200 + 600 Da), in approximately equal amounts. The general information afforded by the present observations support the hypothesis that ionic F is released progressively during the metabolism of MFP bound to alpha2-macroglobulin and C3. These phenomena explain why comparable effects to those obtained with 30 mg F/d of NaF could by obtained with one half the dose of MFP.

Outcome of hip fractures among elderly subjects

This paper reports a retrospective study (1979-1995) on 200 patients (154 women and 46 men), 50-101 years old, who received medical attention because of unilateral hip fracture. Nine women and four men fractured twice. In 75 percent of women and 90 percent of men, surgery was carried out between one and five days after fracture. A non significant greater proportion of women (14/154) than men (6/46) died in the first year after injury (X2=3.459, P = 0.062). Survival was assessed using Cox proportional hazards model. Survival was a function of age (P = 0.000) and sex (P = 0.008). After adjustment to a common mean age (79 years), the median survivals for men and women were 3.9 and 8.4 years, respectively. Controlled concurrent life-threatening diseases, the king of fracture [medial (subcapital and transcervical) or lateral (inter- and subtrochanteric)] and the type of prosthesis (total/partial articulation replacement) had no significant impact on survival. No differences in evolution were observed: 80 percent returned to their ambulatory status before injury, 8.5 percent required walking aids and 5.5 percent could not walk. The overall information afforded by this study suggests that with worldwide improvement of hip fracture outcome, the cost/effectiveness of surgical treatment of hip fracture may become, from the standpoint of public health investment, a favorable alternative with respect of cost/effectiveness of prevention-treatment measures.